A Sexy DSL for JavaScript Arguments

I was working on one of my Node.js libraries and noticed I was doing something silly:

Karait (https://github.com/bcoe/karait)

There’s a lot of ritual around dealing with optional arguments and default parameters!

I did a little literature review, and found this problem was pretty widespread.

Other Examples

Node MongoDB Native (https://github.com/christkv/node-mongodb-native)

Express (https://github.com/visionmedia/express)

JSDom (https://github.com/tmpvar/jsdom)

The Solution? Sexy Arguments

sexy-args is a simple library and DSL for:

• Handling optional arguments.
• Enforcing types.
• Handling default values.

sexy-args enforces sane defaults:

• Arrays default to [].
• Objects default to {}.
• functions default to function() {}.
• Extend is used by default when assigning default values for an object.
• The common options (optional), callback, format is used by default:

So,

Becomes:

Examples After Applying Sexy-Args

Here’s what those prior examples would look like if they were using sexy-args:

Karait

Express

JSDom

I think this is much cleaner, which is the goal of sexy-args. Why repeat ourselves all the time when defining functions?

Rituals, like those surrounding handling optional arguments, help JavaScript get a bit of a reputation for being ugly. I feel it’s maleable enough language that steps can be taken to improve on things.

I’ve made the library available here:

https://github.com/bcoe/node-sexy-args

And here’s the Karait library, which I’ve updated to use Sexy-Args:

https://github.com/bcoe/karait

— Benjamin Coe (@benjamincoe)